Front projection screens are those which are viewed from the same side of the screen from which the image is cast onto the screen and are generally available in two types--manual screens, such as those used in the home for viewing slides or home movies, and electrically powered screens as may be used in a conference room or board room. Electrically powered projection screens comprise an AC motor for driving the roller about which the screen is wound and are generally operated via remote control or with controls located on a wall in the room in which the projection screen is installed. A casing is provided which houses the screen, the roller about which the screen is wound and the motor. Two types of AC motors have been utilized to power projection screens. Traditionally, gear motors as are available from Emerson Electric are positioned near the roller of the projection screen. Projection screens using gear motors include the Ambassador, Rolleramic and LumaLectric Models available from Draper Shade & Screen Co., Inc. of Spiceland, Ind. For smaller screens, a gear motor may draw approximately 1.4 amps and produce 38 inch-pounds of torque and 35 rpm. For larger screens, a motor drawing 3 amps and producing 240 inch-pounds of torque at 13.6 rpm may be required.
More recent advances in technology have produced tubular AC motors which are able to fit within the roller of the projection screen. Thus, tubular motors are advantageous in that the size of the casing required to house the projection screen's working components is significantly less than for an electrically powered projection screen which utilizes a traditional gear motor. Tubular motors are available from such sources as Somfy of Cluses, France and typically draw 1.1 amps and produce 50 inch-pounds of torque at 35 rpm. Examples of projection screens which use a tubular AC motor encased within the roller include the Targa, Envoy, Artisan/Series E and Premier Series models offered by Draper Shade & Screen Co., Inc. of Spiceland, Ind.
The requirement of electrically powered projection screens to be connected to an AC power source presents difficulty when installing an electrically powered projection screen in an existing office or room, as power must be routed from an existing power source to the projection screen. Should the consumer be leasing office space which cannot be modified, installation of an electrically powered projection screens may not be feasible to these power requirements. Furthermore, if the screen is installed in a leased office space, the cost of removing the screen and reinstalling it in another installation site is prohibitive. Thus, it is desirable to provide a portable, electrically powered projection screen which may be easily retrofitted into an existing installation site.
The concept of providing an electrically powered projection screen driven by a DC motor is very attractive as a DC powered projection screen system would to be portable and may be retrofitted into an existing installation site at a reasonable cost. However, difficulties are encountered in obtaining a DC motor of appropriate dimensions which is capable of winding and unwinding the screen about the roller, particularly when the screen is of a significant size, as DC motors typically provide less torque than AC motors produce. Thus, it is desirable to provide a projection screen which uses a reasonably sized DC motor. Furthermore, such a DC motor should be conservative in the amount of battery power it consumes to roll and unroll the screen. The projection screen system should also be comprised of inexpensive, reliable components and be inexpensive to manufacture. In addition, to limit the size of the casing required to house the projection screen's working components, it is desirable to utilize a tubular DC motor which may be located within the roller.
Projection screens as may be found in a conference room usually comprise a casing housing the screen, the roller and the motor. Fasteners are provided which allow the casing to be suspended from a ceiling, hung flush with the ceiling and/or hung on a wall. In some systems, such as in the Ambassador model projection screen offered by Draper Shade & Screen Co., Inc. of Spiceland, Ind., the casing is installed above the ceiling and has a pivotable door through which the screen is lowered. However, when the fascia of the casing is visible, it is desirable to provide fascias of various textures and colors so that the casing matches the decor of the room in which it is installed. Furthermore, it is quite possible that the decor of the room may change and therefore it is desirable to provide a fascia whose appearance and texture may also be easily changed to match the new color. Therefore, under ideal circumstances, it is desirable to provide a fascia for the casing which may be installed without the use of tools and which is easy to replace and to decorate such as in the application of paint or wallpaper to the fascia. If the fascia may be removed and replaced without the use of tools, easier and quicker access to the working components housed in the casing results. Such access helps to reduce labor costs associated with repairing or maintaining the components housed in the casing. Thus it is desirable to provide a fascia for the casing of a projection screen which is easy to remove, to decorate once removed and to reinstall for both aesthetic and repair and maintenance reasons. It is also desirable to provide a fascia which is inexpensive and easy to manufacture.